Improvement in filters for liquids holding solid impurities



E. S. HUT'CIIINSON.

FILTER FOR LIQUIDS HOLDING SOLID IMPITRITIES.

".PETERS, FNOTO-UTNOGRAPNER, WASHINGTON. D C.

UNITED STATES PATENT OFFICE, I

ELIAS SMITH HUTOHINSON, OF BALTIMORE, MARYLAND.

IMPROVEMENT IN FILTERS FOR LIQUIDS HOLDING SOLID IMPURITIES.

Specification forming part of Letters Patent No. [70,952, dated December 14, 1875; application filed November 12, 1874.

To all whom it may concern:

Be it known that I, ELIAS S. HUTCHINSON, of Baltimore, in the county of Baltimore and State of Maryland, have invented certain improvements in Filters, of which the following is a specification:

My invention relates to that class of filters used for filtering saccharine solutions and other liquids containing solid impurities, the filter being so constructed as to discharge the filtrate continuously, while the solid matter separated therefrom is removed continuously or intermittently, as may be desired.

In the accompanying drawing, Figures 1 and 2 are vertical sections in lines a; a0 and y 3 in Fig. 3, respectively. Fig. 3 is a horizontal section in line 2 2, Fig. 1. Fig. 4 is an elevation of the lower portion of one of the diaphragms with the covering removed.

Likeletters of reference designate like parts in each of the figures.

A represents the top plate or upper head,

and B the bottom plate or lower head, of the filtering-compartment. As shown in the drawing, the side walls of the machine are composed of two opposite plates, 0 C, while the two other walls are composed of sections D D, cast with or forming part of the vertical partitions E E. A sufficient space is left between the upper and lower ends of the partitions and the top and bottom plates of the filter to furnish a free passage for the liquid into and from the difi'erent compartments formed by such partitions. These parts are preferably made of cast-iron when used for filtering liquids that do not chemically react upon the same, although wood or any other material suitable for the liquid desired to be filtered may be employed. The partitions E E are provided with vertical grooves e e, on both sides thereof, extending nearly to the bottom of the partitions, where they open into a transverse channel or groove, f, slightly inclining downward from the center in either direction. The ends of the channel f on both sides of the partition communicate, by passages f f, with a single discharge-pipe, g, on opposite sides of the filter. When the partitions are made of cast-iron they are preferably cast with the side sections D, the joints between the contiguous edges of the sections D being rendered tight by'packing, or in any other suitable manner. These sections and partitions are secured or clamped together by means of the side plates 0 O and connecting tie-rods d d. i

Instead of the sections D D, cast with the partitions E E, the sides of the filter formed by these sections maybe madein one piece, and the partitions fitted in suitablegrooves thereof, or otherwise secured between the same.

The sides of the partitions E E are covered first by a strong sheet, h, of wire-cloth, or finely-perforated plate of suitable strength to form a backing or support for the filteringcloth 2', made of any suitable material, which is applied thereto. Between the wire-cloth h and filtering-cloth i a wire-cloth, h, of finer texture is preferably arranged to prevent the embeddingof the filtering-cloth into the meshes of the coarser wire-cloth backing. On the outside of the filtering-cloth is preferably secured another sheet, is, of wire-cloth ofcoarser texture, for a purpose presently to be explained.

Z is a sliding rod, arranged horizontally and centrally in the machine above the partitions E, and passing through stuffing-boxes l in the side sections. M are cross-heads secured to the rod 1, to which are attached pendent bars or plates m, extending to the bottom of the filteringpartitions, and arranged so as to travel in contact, or nearly so, with the outer wire-cloth k thereof as the rodl is reciprocated, thereby scraping off or removing the superfluous solid matter which collects and adheres to said surfaces. A single plate or scraper may be used, arranged so as to re move the impurities from the two adjacent surfaces of two filtering-partitions, or a separate plate may be used with each surface, as shown in the drawing.

The liquid to be filtered is forced into the above-described apparatus through a pipe, at, in the top plate, under a suitable pressure, in a common manner.

The bottom plate B is constructed with a concave depression, I), and a central dischargeopening, communicating with a downwardlyextending cylindrical reservoir or tube, 0, preferably in length about twice the height of the filter. The lower end of the tube 0 is closed by ahead and striding-box, 0', through which passes a vertical shaft, 10, extending through the tube 0, and projecting into the depression of the head B, where it is provided with a scraper, 19 The latter is preferably made of tangential or curved form, so as to scrape the solid matter which collects in the depression b toward. the central dischargeopening thereof. The shaft 10 is provided with pins or projections 12 operating to agitate the mass contained in the tube 0. q is the final discharge-opening for the solid matter, controlled by a stop-cock or screw, q. The tube 0 is provided with one or more try-cocks, t, by which the consistency of the material therein is readily ascertained.

The liquid to be filtered being forced into the apparatus through the pipe at the top, as above described, the pressure within the filter forces the liquid through the filtering-cloth covering the partitions, and into the vertical grooves or channels thereof, from whence it is conducted by the transverse grooves f and passages f to the discharge-pipes g. The solid matter contained in the liquid collects on the surface of the filtering-cloth, filling up the meshes of the outer wire-cloth covering, thereby forming a filtering medium in addition to the cloth. The rod 1 is slowly reciprocated, either continuously or intermittently, so as to cause the scrapers m to traverse the surface of the wire-cloth k, and prevent such an accumulation of solid matter thereon as would impair or obstruct the action of the filter.- The outer wire-cloth 7c serves not only to protect the filtering'cloth from the wear and action of the scrapers, but its meshes also serve to retain therein a thin layer of the solid matter, thereby increasing the thickness and efficiency of the filtering medium. The

'solid matter removed by the scrapers from the filtering-partitions descends between the partitions into the concave depression I) of the lower head, where it is scraped by the revolving sweep p into the central opening and reservoir 0. This solid matter gradually collects in the reservoir 0, the consistency of the material increasing as the reservoir becomes filled, until that at the bottom of the latter is comparatively solid or free from liquid. The radial pins 10 on the shaft 10 agitate the mass within the reservoir and prevent undue solid.- ification of the material therein at any point, and facilitate the deposition of the solid matter in the lower portion of the reservoir. The valve q is opened from time to time, as required, and the collected impurities driven or forced out. By the use of the try-cocks t the condition and consistency of the material in the reservoir 0 may be readily determined at any time as required.

The body orcentral support E of the filtering-partitions may be composed of vertical rods arranged with sufficient spaces between them for the discharge of the filtrate as it escapes through the filtering-surfaces on either side, or the inner wire-cloth backings It may be supported at short distances apart by any suitable'means, so as to leave a space between them for the escape of the filtrate. The grooves in the partition E. may be arranged in any manner that will convey the liquid to the discharge-pipes.

While I prefer the arrangement of the filtering-partitions vertically, as shown in the drawing, they may, however, be inclined or arranged in any suitable position that will permit of the escape anddischarge of the filtrate and impurities.

For filtering liquids in which the solid impurities or a portion of them arelighter than the liquid, so as to rise to the surface thereof, I construct the under surface of the top plate with a concave-depression scraper and discharge-aperture similar to that of the bottom plate, so that the impurities that rise to the surface can be removed through the top plate, while the heavier impurities, if any there be,

can be removed through the bottom plate as above described. The liquid to be filtered in this case is forced into the apparatus at any other suitable point from that shown in the drawing.

In filtering liquids that (lo-not contain sufficient or suitable solid matter to form acoatiug on the surface of the filtering-cloth, such coating may be supplied by mixing with water or the liquid to be filtered a quantity of suitable solid matter, such as paper-pulp, and forcing it through the filter until the required coating is produced.

What I claim as my invention is-- l. The combination, with the outer case, filtering-partitions, and scrapers m, of the bottom plate B, constructed with a depression, b, forming a receptacle for the solid matter detached from the filtering-partitions by the scrapers, substantially as hereinbefore set forth.

2. The combination, with the outer case and filtering-partitions, of a head provided with depression 12 and scraper p substantially as and for the purpose hereinbefore set forth.

3. The combination, with the bottom plate B and reservoir 0, of the shaft 1;, scraper p and agitating-arms 10, substantially as andfor the purpose hereinhefore set forth.

ELIAS SMITH HUTOHINSON.

Witnesses:

JNo. J. BONNER, EDWARD WILHELM. 

